In the sense of this description and the claims, a cable is understood to be any elongated, flexible, or elastic material for the transport of energy, information, or materials, in particular, but not exclusively, an electrical cable, an optical cable (including, for example, optical fibers), a delivery pipe, etc.
A solution is known from JP 59.149276 in which the cable is mounted on an elastic flat spiral spring and can be rotated with the axial spring end. Disadvantages of this solution include, first, its large diameter and, second, the rather large restoring moment of the rotating part in the limiting positions and changing with the rotations.
A solution is known from DE 402 6782 in which a helical carrier body has all inflection point and the cable is embedded and in this way guided with a force fit in the carrier body.
From DE 199 28 731 C2, a device for winding, unwinding, and storing elongated, flexible parts is known, which is not formed, however, as a rotation transformer. This device is used for the purpose of holding a cable, like in a cable drum, wherein this cable can be removed from the drum by pulling on the two cable ends. Here, the cable has no guidance by a bearing axis, however, and due to the only two spaces between adjacent separation discs, a controlled winding and unwinding, like that required for a precise rotation transformer, is not possible.
DE 703 0 622 and DE 703 1 318 disclose a device for winding electrical measurement cables and a cable and hose box as their respectively subject matters. In both publications, however, the problem of rotation transmission is not addressed in any way; instead both publications are concerned only with the storage and release of cables, and the problem of rotating the cable ends relative to each other plays no role.
Finally, DE 40 18 440 A1 shows a spiral line arrangement which is connected on one end to a device that can rotate back and forth about a rotational axis, and on the other end to a stationary device, and which can rotate in or out with the rotation of the rotatable device. The solution proposed is technically exceedingly complicated, because a synchronizing drive for the individual cascade arrangements is necessary.
Therefore, there is the task of constructing a rotation transformer for a cable connection that can be produced simply and cost-effectively, generates no restoring moments, requires no special drive, and places no special requirements on the cable configuration or embedding.